Employee Benefit Plans (Details 2) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Before tax basis amount in accumulated other comprehensive loss.
Total recognized at December 31	$ 5,511	$ 6,478
U.S. [Member]
Before tax basis amount in accumulated other comprehensive loss.
Net actuarial loss	4,653	4,809
Prior service (credit) costs	4	(5)
Total recognized at December 31	4,657	4,804
International [Member]
Before tax basis amount in accumulated other comprehensive loss.
Net actuarial loss	1,145	1,143
Prior service (credit) costs	106	120
Total recognized at December 31	1,251	1,263
Other Benefits [Member]
Before tax basis amount in accumulated other comprehensive loss.
Net actuarial loss	(82)	367
Prior service (credit) costs	(315)	44
Total recognized at December 31	$ (397)	$ 411